—The police have caught the murderer.

　　   —Yes, and he admitted ________ his boss on a rainy night seven years ago.

A．to kill

B．to have killed

C．having killed

D．have been killing

关于肝内胆管结石特点的叙述错误的是

A．肝内胆管结石为原发性结石

B．右肝管多于左肝管

C．部分可排出形成肝外胆管结石

D．多为胆色素结石或以胆色素结石为主的混合性结石

E．治疗难度相对大